title: Control failure likelihood and spatial dependence of insecticide resistance in the tomato pinworm, Tuta absoluta.
abstract: BACKGROUND
  Insecticide resistance is a likely cause of field control failures of Tuta absoluta, but the subject has been little studied. Therefore, resistance to ten insecticides was surveyed in seven representative field populations of this species. The likelihood of control failures was assessed, as well as weather influence and the spatial dependence of insecticide resistance.
  
  
  RESULTS
  No resistance or only low resistance levels were observed for pyrethroids (bifenthrin and permethrin), abamectin, spinosad, Bacillus thuringiensis and the mixture deltamethrin + triazophos (<12.5-fold). In contrast, indoxacarb exhibited moderate levels of resistance (up to 27.5-fold), and chitin synthesis inhibitors exhibited moderate to high levels of resistance (up to 222.3-fold). Evidence of control failures was obtained for bifenthrin, permethrin, diflubenzuron, teflubenzuron, triflumuron and B. thuringiensis. Weather conditions favour resistance to some insecticides, and spatial dependence was observed only for bifenthrin and permethrin.
  
  
  CONCLUSIONS
  Insecticide resistance in field populations of the tomato pinworm prevails for the insecticides nowadays most frequently used against them-the chitin synthesis inhibitors (diflubenzuron, triflumuron and teflubenzuron). Local selection favoured by weather conditions and dispersal seem important for pyrethroid resistance evolution among Brazilian populations of T. absoluta and should be considered in designing pest management programmes.
authors.affiliation: Departamento de Biologia Animal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
authors.forename: Gerson A
authors.initials: GA
authors.lastname: Silva
authors.forename: Marcelo C
authors.initials: MC
authors.lastname: Picanço
authors.forename: Leandro
authors.initials: L
authors.lastname: Bacci
authors.forename: André Luiz B
authors.initials: AL
authors.lastname: Crespo
authors.forename: Jander F
authors.initials: JF
authors.lastname: Rosado
authors.forename: Raul Narciso C
authors.initials: RN
authors.lastname: Guedes
mesh_terms: D000818:Animals; D001938:Brazil; D007300:Insect Control; D007305:Insecticide Resistance; D007306:Insecticides; D007814:Larva; D018551:Solanum lycopersicum / Q000469:parasitology*; D009036:Moths; D014887:Weather
chemical_list: D007306:Insecticides